PRS400 Laboratory Welding System

Statoil Petroleum ASA

The project

The Pipeline Repair Systems (PRS) laboratory at our customer’s site in Norway required a state-of-the art facility to test and qualify a range of weld applications at simulated sea-water depths of up to 4,000 metres, that is, at pressures up to 400 times sea-level atmospheric pressure. It consists of a gas-filled pressure chamber with a capacity of approximately four cubic metres, which has internal fittings to accommodate a variety of different equipment. It is used both to test equipment and to develop weld procedures and parameters for planned operations and contingency work. The pressure capability means it can be used to plan and qualify subsea operations around the world, not just in North Sea fields.

Our Projects

Our brief

Isotek was involved in critical elements of the chamber, including the design, fabrication and testing of welding manipulators and the integrated weld control system, including a 400bar arc viewing camera, which gives our customer full research and development capability.

The internal welding manipulators allow both orbital and tee-welding applications to be tested, and can also be used in a 90° configuration for clad pipe internal welding. It is currently being used to validate the weld procedures for the Zeepipe IIA and Johan Sverdup (Statpipe) remote hot tap application welds planned for offshore field implementation in 2017 and 2018.

This project was challenging because of the need to produce a single control system that incorporated large parts of three distinct welding systems – the TIG orbital, the MIG orbital and the MIG internal saddle tee-welder.

The results

The PRS equipment was successfully tested at the customer’s PRS base at Killingøy in Norway. The test included a full 6-pass internal saddle weld in a hot-tap pipe setup at a simulated depth of 4,000 metres, a world record-breaking achievement for MIG welding. The capability to perform this type of weld in the field represents the opportunity for considerable cost and time savings for operators. This is a total step change in subsea welding technology; the potential for improved cost control and time-savings for operators in all locations is considerable.

The feedback

" I would like to take this opportunity to thank Isotek and PRS JV for their good work and cooperation who together have completed the job of getting the plant operational. We will now consider the possibility of signing an official Guinness World Record.
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